Oppo Find 7 features QHD display and 50MP images

Several manufacturers were rumored to launch a smartphone with a QHD-display (2560x1440 pixels) at Mobile World Congress in Barcelona but none of the models introduced at the show featured one of the high-resolution screens. Now the wait is over. The Chinese smartphone manufacturer Oppo has introduced their latest flagship model, the Find 7. This makes the Find 7 the first smartphone to feature a QHD screen. The pixel density of the 5.5-inch display is a staggering 538ppi which should make for ultra-sharp rendering of images and text.

Not only is the Find 7's screen top-notch, the new device comes with top-end specifications all around. The Android OS is powered by a Snapdragon 801 SoC and 3GB RAM. Rapid Charge technology will let you charge the Find 7's 3000mAh battery to 75% in only 30 minutes and a MicroSD slot allows for easy storage expansion.

The Camera

With a 13MP 1/3.06-inch Sony Exmor CMOS sensor and F2.0 aperture, the camera specifications look decent, but not anything out of the ordinary. The Find 7 also comes with a "Super Zoom" software feature that allows for the capture of 50MP images. To achieve this the camera takes a burst of 10 images, then selects the four best shots and combines them into a single 50MP frame. Brief communication with Oppo indicates they are using a 'superposition' technique to create the 50MP file. We surmise the underlying principle is similar to that used by the Hasselblad H4D-200MS to create 200MP images from a 50MP sensor (note the similar 4x increase in resolution over the native sensor resolution). Such super-resolution techniques create a higher-than-native resolution image by relying on small movements from shot-to-shot to allow for high frequency detail - beyond what the sensor could natively represent accurately - to be recovered. For example, consider the following example where the sensor (indicated by the pixels outlined in red) is imaging black lines with widths on par with pixel widths.

An illustrative example of a sensor's pixel grid (pixels outlined in red) recording high frequency detail on par with the sensor's frequency. The color (albeit black, white, or grey here) recorded at any pixel is shown within each pixel. Graphic: Photo Acute

Depending on the alignment of the sensor to these alternating black and white lines, the sensor may (left, in the image above) or may not (right, in the image above) accurately represent the original pattern. Remember: a pixel just tallies up the amount of light entering it, and on the right, any pixel is just recording 50% white and 50% black - that is, grey. This loss of contrast - resulting from the pattern being averaged across pixels - results in a decrease in resolving ability of high frequency detail. Now imagine shifting the sensor such that the pixels on the right were to align with the pattern just as the pixels on the left initially did in the example above. This might allow for the recovery of additional detail. Sophisticated software algorithms can 'look' for this sort of detail across multiple shots to increase the effective resolution of capture. Oddly enough, the small movements your hands make from shot-to-shot - which you might initially imagine as deleterious - end up potentially increasing the spatial resolution of the sensor. Simply by allowing for many different alignments of the sensor's pixel grid to the real-world detail being projected onto it. You can read more about the basic principles of super-resolution and how it is used to recover sub-pixel information in Photo Acute software here.

We do note that for this method to be effective, the lower 'native' resolution images need to be aligned with sub-pixel precision. However, with faster processors as well as accelerometer information regarding shot-to-shot movements, we imagine this is not too large an issue with modern hardware.

The 50MP Image - Any Good?

While Engadget shows a sample that does not look too impressive at 100% view and has the appearance of an upsampled file, the technique might have its merits in a phone for creating a better, native 13MP resolution file (downsampled from the 50MP file). Although Oppo confirmed that a lower, 'native' resolution output using their "Super Zoom" technology would not be available (single shot 13MP - including RAW - output is still available), users can always downsample the 50MP file to 13MP in any photo-editing suite themselves. Furthermore, any multi-shot technique has the potential to reduce noise - especially important for the small sensors found in phones.

All that said, given the feature's "Super Zoom" moniker we would expect the large images to, at the very least, be used for a more efficient digital zoom. It'll be interesting to see how it compares to Nokia's PureView and more conventional systems once more samples are available.

The Oppo Find 7 is the first smartphone with a QHD screen.

The camera module comes with a 13MP Sony sensor and a F2.0 aperture.

Further Details

In addition the Oppo Find 7 is also the first Android device to offer Raw capture. In video mode you can capture 4K footage and 120 fps slow motion video at 720p resolution. For self-portraits and video-calls there is a 5MP F2.0 front camera.

The Find 7 is also available as a version with 1080p display that comes with a slightly downgraded CPU, 2GB RAM and less onboard-storage, but the camera specification is identical to the QHD-model. The latter will retail at 3,498 CNY (approximately $565), while the version with 1080p-screen will set you back 2998 CNY (approximately $480). There is no word yet on availability outside of China.

Comments

50 down-sampled with a divisor of 9 (3*3) will give each resulting pixel a below average noise of 3*3 pixels.

And give a 5.5 Mpix image, more than enough for most.

The only thing this baby needs is a cam software that does this in background, after each shot, so you save post-processing.

And with selectable curves/settings for low ISO high brightness, HDR scenes and high iso / low light scenes.

In addition to all that, it has the best screen, best SoC, best amount of RAM, best battery capacity (sans phablets) and 32GB memory model available (shame on you Sony and Samsung for your 16GB on-board flash memory variants only).

I already have a smartphone in which I don't use the camera but use a 'real' camera.I'm interested in the camera but don't need another phone.It does allow the telcos to be part of the distribution but can I get one without having a phone plan?If I want to use the Nokia 1020 or some advanced imaging device I buy a phone I don't use or make yet another switch to another phone plan.But an advanced imaging device can be connected to some communications system or use WiFi.I'm thinking, will there be small computers carried by people which will handle imaging and communications and avoid the need to cram it all in one device.The Google modular phone seems to be a step in this direction where camera modules are swapped on a chassis which has a phone and so on.

That's a good point, LensBeginner. You're absolutely right - to a certain degree these sorts of tricks can already be done manually in post-processing (especially if the RAW data is available).

But that doesn't take away from the fact that having an app - a native one particularly - that does it well is relevant to the end-user. Furthermore, I do wonder if accelerometer data from the phone could speed up the alignment process.

And re: older devices that did this - some older videocameras utilized pixel-shift CCDs to create greater-than-SD content back in the day. As Sirander indicates above, it's old tech, but it (sometimes) works. Rather well too, might I add - especially if you subsequently downsize to the native resolution (you'll notice MTF & SNR increases).

More than one camera has the ability to combine images to produce higher megapixel counts, or HDR, whatever. The problem is that any movement in the scene while the exposures are taken, that is resolvable by the sensor will result in blur, negating any image gain the extra pixels would provide in the area that moved.I will add that Oppo makes excellent Blu-ray players.

Just to be clear: super-resolution is completely different from HDR. The latter deals with circumventing the limited range of brightnesses the sensor can record, while the former is an attempt to increase resolved detail.

Yes, moving objects may not see as much gain in quality (if any at all), but for the many of us that shoot more static scenes with smartphones, the potential gain may be significant. We really won't know until we've got one in our hands to test.

Good point about Oppo Blu-Ray players. It's funny when you consider Oppo's players had very good DVD upscaling algorithms :)

We got that, however the goal is similar.The point of "more Megapixels", or "more exposures", is that you can use the surplus data (using the proper procedure e.g. exposure bracketing, focus bracketing, etc.) to increase either detail (super resolution), DR (HDR), SNR (supersampling) or DoF (focus stacking). An maybe even some other thing that I missed.

Because it would almost impossible to scale this pixel density up to a much larger device and not have huge issues with dead pixels etc. It's like in the early days of digital when Canon released 1Ds, the yields from a FF sensor were dramatically lower than crop sensor with as much as 50% failure rate and hence the high cost.

Now of course you failed to mention we have just seen the release of 4K monitors @ 24" size that are reasonably affordable, but these are still only about 200dpi. 531dpi would be higher than even 8K. We will see this happen but not for many many years at an affordable price point.

Screen resolution. Can someone explain to me the advantage of 586 ppi on a smartphone over one that's around, say 300ppi?

I am very near-sighted so occasionally, without corrective lenses I will hold my phone screen within several inches of my eyes. Even at that range I cannot discern individual pixels. What is the use of more resolution if the limitations of 'perfect' human vision means one is unable to perceive it? On a tiny screen is a 1080p film perceptually any better than 720p? I think not.

The numbers game in screen resolution terms is getting increasingly ridiculous as it goes increasingly beyond the useful. And it isn't as if there isn't a price to pay in terms of battery drain.

we'll have to wait and see what the screen actually looks like when we got one into our hands. One advantage to me is that you simply get more content on the screen, for example in a browser. You get a good overview over a website and then can zoom in to actually read it, at least that's the way I browse the web on my phone. That said, it already works pretty well with the current 1080p screens, not sure how much of an advantage the QHD screen will be, it's got more pixels than many computer screens.

Whenever screen resolutions have gone up, I could see smaller text and images were sharper. I've only seen computers up to QHD, and cells up to 1080p, so it's possible QHD on a cell goes beyond the limits of reasonable, but I'll hold off judgement until I see it. So far, it's always helped.

More colors, better contrast, more 3d like immersive image.To me theres a great diference in sharpness from galaxy note 1 800p to 1080p. But i guess the proposition is not only to increase the detail per si but to allow this other characteristcs to evolve too. Some say 8k is the maximum perceived resolution by the eye, but i guess the world is not rendered in 8k. it is? So they will keep going, and great numbers sell more to people with no knowlege. But yeah choose what satisfy you if you dont see any diference don t buy it. :)

Why do you think everybody has poor vision like yourself? Also, using video as a standard is wrong.. unless you are viewing a direct BluRay rip, the quality of the video file is going to be the limiting factor, not the screen.. this doesnt mean you will not see differences in other things like photos.

FFS. When are camera manufacturers going to start quoting sensor sizes in millimetres? This 1/x.x business is needlessly confusing. OK, so maybe that's the point - big numbers sound more impressive to the inexperienced, even if they have a 1 over them - but still, millimetres (or even millimeters) would make imaging chips a lot easier to compare. It would make it easier to estimate the 35mm equivalent focal length of the lenses, too.

C'mon DPReview - how about you start doing it unilaterally? You're influential enough that maybe you could change industry policy.

Shadowww: The image was very confusing until I saw the error in it. The yellow line is supposedly "Sigma 24-70 f/2", but the line goes from 70 to 200 mm along the f/2.8 line. The legend for the purple line says generic 70-200 f/2.8, but the line itself goes from 24 to 70 mm along the f/2 line.

Whats real funny, is that we dont even have a full frame sensor with that many pixels. I dont understand the point of this crap. They never perfect 8 mp sensor and went pretty much straight to 40-50. My lumia 1520 20mp cam is crap. that must be a lot worse.

I can see this technique would increase color resolution, since due to movement you could have different color pixels overlap, thus compensating for bayer demosaicing losses. I am also wondering if Fuji will make a phone sensor with small and large pixels, let's say 8M+8M, thus increasing low light performance and DR without multiple frames. Small pixels could also be used to increase resolution with multiple frame techniques too. Any opinions on this?